Wells are commonly used to access regions below the earth's surface and to acquire materials from these regions, for instance during the location and extraction of petroleum oil hydrocarbons from an underground location. The construction of wells typically includes drilling a borehole and constructing a pipe structure within the borehole. Upon completion, the pipe structure provides access to the underground locations and allows for the transport of materials to the surface.
During the construction and operation of a well, various monitoring systems may be used to evaluate the integrity of the well's underground structures. For example, acoustic monitoring systems may be used to inspect a pipe casing and its surrounding cement support structure. These systems may be placed within the pipe casing and lowered through the wellbore, and generally include a transmitter that directs acoustic energy towards the casing, and a receiver that detects acoustic energy reflected from the casing and from the various materials beyond. Based on the measured reflections, the monitoring system provides information regarding the casing and its surrounding environment.
Like reference symbols in the various drawings indicate like elements.